And before all the B guys get too smug, ask yourselves what would happen in your machine if critical displays and systems continually were shuttled between busses by an intermittent electrical problem?
A newish 737-300 at America West suffered EFIS blanking, etc., that was traced to intermittent electrical supply connector contacts. The crew took it in stride.
Well designed systems will accommodate intermittents that would cause cumulative errors in less robustly designed systems. A/B will figure it out and fix it, retrofitting the robustness should have been there in the beginning.
GB